Working on customer site recently I was perplexed by why I could not create an unattend.xml file from within MDT 2010 for my custom Windows 7 x32 image. So I did some digging and finally located a program manager who could explain to me what was going on. The summary is that;
- if you run Windows 7 x32 and WAIK x32 you can create unattends for both x64 and x32 custom images.
- if you run Windows 7 x64 and WAIK x64 you can not create unattends for x32 custom images.
- running x32 WAIK on Windows 7 x64 is not supported.
What the program manager said…
I understand that its an annoyance that on x64 machines, you can only create catalogs for x64 WIM’s. Back in Vista timeframe, a decision was made to use the servicing stack binaries in the image you’re trying to generate a catalog for, in order to create the catalog (as opposed to having WAIK carry those binaries, which created a servicing burden for WAIK). This was a better overall design strategy since it now allowed WSIM to work ok, independent of any changes made to the servicing stack binaries of the image you’re trying to generate a catalog for.
However, one side consequence is that the architecture and flavour of the WSIM tool has to match the architecture of the servicing stack ( that was extracted from the WIM ). Since a 32 bit WIM carries only a 32 bit servicing stack in it, 64 bit WSIM cannot generate a catalog due to architecture mismatch. ( Hence one can use only 32 bit OPK for this.) However a 64 bit WIM carries both , a 32 bit and a 64 bit servicing stack in it. Thus one can use either a 64 bit or a 32 bit WSIM to generate a catalog for such a WIM.
I think they have made the right trade off here in terms of reducing the support complexity for Windows System Image Manager. The down side is it might introduce a few extra steps for those of us creating custom images.
So if your admin machine is x64 when you create an unattend for a custom image you have to create it against the RTM media. Then copy the resultant XML to the correct place for your x32 custom image to use when it is installed. Alternatively use an x32 workstation to create all your unattends.
This post was contributed by Richard Trusson, a Senior Consultant with Microsoft Services, UK.